The present invention relates to method and apparatus for preventing forces applied to a control shaft from dislodging the associated control device (e.g., a potentiometer) from a printed circuit board.
Electronic instruments often include potentiometers, variable capacitors, variable inductors, etc. having control shafts which extend through a front panel of the instrument so that their position can be controlled by the instrument user. Most often, the potentiometer for other variable control devices is fixedly mounted to the front panel, and includes wires connecting it to the circuit of which it forms a part. This adds to the cost of assembly of the instrument with which the control device is associated, since the potentiometer or other control device must be manually inserted through the front panel of the instrument, and then attached thereto. Further labor is required in connecting the wires between the control device and the printed circuit (PC) board upon which the other electronic components are mounted.
It has become increasingly popular to mount as many components as possible on a single printed circuit board, since the insertion and soldering of components to printed circuit boards can be automated to a substantial extent. When a potentiometer or other control device is directly mounted on the PC board, however, the radial and axial forces applied to the shaft by the user during manual adjustment of the potentiometer can cause it to become disattached from the printed circuit board. It is therefore desirable that radial and axial loading on a control shaft of a PC board-mounted control device be minimized.